List 集合初始化

Arrays 工具类

// 生成的list不可变
List list = Arrays.asList(“1”, “2”, “3”);
System.out.println(list);
输出
: [1, 2, 3]

// 如果要可变需要用ArrayList包装一下
List numbers = new
ArrayList<>(Arrays.asList(“1”, “2”, “3”));
numbers.add(“4”);
System.out.println(numbers);
输出
: [1, 2, 3, 4]

Java8 Stream

List list = Stream.of(“1”, “2”, “3”).collect(Collectors.toList());
System.out.println(list);
输出
: [1, 2, 3]